<?php
/**
 * @link https://craftcms.com/
 * @copyright Copyright (c) Pixel & Tonic, Inc.
 * @license https://craftcms.github.io/license/
 */

namespace craft\helpers;

use Craft;
use craft\elements\Asset;
use craft\errors\InvalidHtmlTagException;
use craft\image\SvgAllowedAttributes;
use craft\web\View;
use DOMElement;
use enshrined\svgSanitize\Sanitizer;
use Symfony\Component\DomCrawler\Crawler;
use Throwable;
use yii\base\Exception;
use yii\base\InvalidArgumentException;
use yii\base\InvalidConfigException;

/**
 * Class Html
 *
 * @author Pixel & Tonic, Inc. <support@pixelandtonic.com>
 * @since 3.0.0
 */
class Html extends \yii\helpers\Html
{
    /**
     * @since 5.6.0
     */
    public const TITLE_TAG_RE = '/<title(\s+([\s\S]*?))?>.*?<\/title>\s*/is';

    /**
     * @var array List of tag attributes that should be specially handled when their values are of array type.
     * In particular, if the value of the `data` attribute is `['name' => 'xyz', 'age' => 13]`, two attributes
     * will be generated instead of one: `data-name="xyz" data-age="13"`.
     * @since 4.0.0
     */
    public static $dataAttributes = [
        'aria',
        'data',
        'data-hx',
        'data-ng',
        'hx',
        'ng',
    ];

    /**
     * @var string[]
     * @see _sortedDataAttributes()
     */
    private static array $_sortedDataAttributes;

    /**
     * Will take an HTML string and an associative array of key=>value pairs, HTML encode the values and swap them back
     * into the original string using the keys as tokens.
     *
     * @param string $html The HTML string.
     * @param array $variables An associative array of key => value pairs to be applied to the HTML string using `strtr`.
     * @return string The HTML string with the encoded variable values swapped in.
     */
    public static function encodeParams(string $html, array $variables = []): string
    {
        // Normalize the param keys
        $normalizedVariables = [];

        foreach ($variables as $key => $value) {
            $key = '{' . trim($key, '{}') . '}';
            $normalizedVariables[$key] = static::encode($value);
        }

        return strtr($html, $normalizedVariables);
    }

    /**
     * Converts spaces into `%20` entities.
     *
     * @param string $str
     * @return string
     * @since 4.0.4
     */
    public static function encodeSpaces(string $str): string
    {
        return str_replace(' ', '%20', $str);
    }

    /**
     * Disables any form inputs in the given HTML.
     *
     * @param callable|string|null $html
     * @return string|null
     * @since 5.6.0
     */
    public static function disableInputs(callable|string|null $html): ?string
    {
        if (is_callable($html)) {
            // Call it to get the HTML, but disregard the JS
            Craft::$app->getView()->startJsBuffer();
            try {
                $html = $html();
            } finally {
                Craft::$app->getView()->clearJsBuffer();
            }
        }

        if ($html === null || $html === '') {
            return $html;
        }

        $crawler = new Crawler("<html><body>$html</body></html>");

        $inputContainers = $crawler->filter('.field > .input');
        foreach ($inputContainers as $inputContainer) {
            /** @var DOMElement $inputContainer */
            $class = array_filter(explode(' ', $inputContainer->getAttribute('class')));
            $class = array_unique([...$class, 'disabled']);
            $inputContainer->setAttribute('class', implode(' ', $class));
        }

        $inputs = $crawler->filter('input,textarea,select,button:not(.fieldtoggle)');
        foreach ($inputs as $input) {
            /** @var DOMElement $input */
            if (!$input->hasAttribute('disabled')) {
                $input->setAttribute('disabled', '');
            }
        }

        return $crawler->filter('body')->first()->html();
    }

    /**
     * Generates a hidden CSRF input tag.
     *
     * @param array $options The tag options in terms of name-value pairs. These will be rendered as
     * the attributes of the resulting tag. The values will be HTML-encoded using [[encode()]].
     * If a value is null, the corresponding attribute will not be rendered.
     * See [[renderTagAttributes()]] for details on how attributes are being rendered.
     * @return string The generated hidden input tag
     * @since 3.3.0
     */
    public static function csrfInput(array $options = []): string
    {
        $request = Craft::$app->getRequest();
        $async = ArrayHelper::remove($options, 'async')
            ?? ($request->getIsSiteRequest() && Craft::$app->getConfig()->getGeneral()->asyncCsrfInputs);

        if (!$async) {
            Craft::$app->getResponse()->setNoCacheHeaders();
            return static::hiddenInput($request->csrfParam, $request->getCsrfToken(), $options);
        }

        Craft::$app->getView()->registerHtml(
            Craft::$app->getView()->renderTemplate(
                '_special/async-csrf-input',
                [
                    'url' => UrlHelper::actionUrl('users/session-info'),
                ],
                View::TEMPLATE_MODE_CP,
            )
        );

        return static::tag('craft-csrf-input');
    }

    /**
     * @inheritdoc
     */
    public static function beginForm($action = '', $method = 'post', $options = []): string
    {
        if (!isset($options['accept-charset'])) {
            $options['accept-charset'] = 'UTF-8';
        }

        return parent::beginForm($action, $method, $options);
    }

    /**
     * Generates a hidden `action` input tag.
     *
     * @param string $route The action route
     * @param array $options The tag options in terms of name-value pairs. These will be rendered as
     * the attributes of the resulting tag. The values will be HTML-encoded using [[encode()]].
     * If a value is null, the corresponding attribute will not be rendered.
     * See [[renderTagAttributes()]] for details on how attributes are being rendered.
     * @return string The generated hidden input tag
     * @since 3.3.0
     */
    public static function actionInput(string $route, array $options = []): string
    {
        return static::hiddenInput('action', $route, $options);
    }

    /**
     * Generates a hidden `redirect` input tag.
     *
     * @param string $url The URL to redirect to
     * @param array $options The tag options in terms of name-value pairs. These will be rendered as
     * the attributes of the resulting tag. The values will be HTML-encoded using [[encode()]].
     * If a value is null, the corresponding attribute will not be rendered.
     * See [[renderTagAttributes()]] for details on how attributes are being rendered.
     * @return string The generated hidden input tag
     * @throws Exception if the validation key could not be written
     * @throws InvalidConfigException when HMAC generation fails
     * @since 3.3.0
     */
    public static function redirectInput(string $url, array $options = []): string
    {
        return static::hiddenInput('redirect', Craft::$app->getSecurity()->hashData($url), $options);
    }

    /**
     * Generates a hidden `failMessage` input tag.
     *
     * @param string $message The flash message to shown on failure
     * @param array $options The tag options in terms of name-value pairs. These will be rendered as
     * the attributes of the resulting tag. The values will be HTML-encoded using [[encode()]].
     * If a value is null, the corresponding attribute will not be rendered.
     * See [[renderTagAttributes()]] for details on how attributes are being rendered.
     * @return string The generated hidden input tag
     * @throws Exception if the validation key could not be written
     * @throws InvalidConfigException when HMAC generation fails
     * @since 3.6.6
     */
    public static function failMessageInput(string $message, array $options = []): string
    {
        return static::hiddenInput('failMessage', Craft::$app->getSecurity()->hashData($message), $options);
    }

    /**
     * Generates a hidden `successMessage` input tag.
     *
     * @param string $message The flash message to shown on success
     * @param array $options The tag options in terms of name-value pairs. These will be rendered as
     * the attributes of the resulting tag. The values will be HTML-encoded using [[encode()]].
     * If a value is null, the corresponding attribute will not be rendered.
     * See [[renderTagAttributes()]] for details on how attributes are being rendered.
     * @return string The generated hidden input tag
     * @throws Exception if the validation key could not be written
     * @throws InvalidConfigException when HMAC generation fails
     * @since 3.6.6
     */
    public static function successMessageInput(string $message, array $options = []): string
    {
        return static::hiddenInput('successMessage', Craft::$app->getSecurity()->hashData($message), $options);
    }

    /**
     * @inheritdoc
     */
    public static function tag($name, $content = '', $options = [])
    {
        return parent::tag($name, $content, static::normalizeTagAttributes($options));
    }

    /**
     * @inheritdoc
     */
    public static function beginTag($name, $options = [])
    {
        return parent::beginTag($name, static::normalizeTagAttributes($options));
    }

    /**
     * @inheritdoc
     * @since 3.3.0
     */
    public static function a($text, $url = null, $options = []): string
    {
        if ($url !== null) {
            // Use UrlHelper::url() instead of Url::to()
            $options['href'] = UrlHelper::url($url);
        }

        return static::tag('a', $text, $options);
    }

    /**
     * Appends HTML to the end of the given tag.
     *
     * @param string $tag The HTML tag that `$html` should be appended to
     * @param string $html The HTML to append to `$tag`.
     * @param string|null $ifExists What to do if `$tag` already contains a child of the same type as the element
     * defined by `$html`. Set to `'keep'` if no action should be taken, or `'replace'` if it should be replaced
     * by `$tag`.
     * @return string The modified HTML
     * @since 3.3.0
     */
    public static function appendToTag(string $tag, string $html, ?string $ifExists = null): string
    {
        return self::_addToTagInternal($tag, $html, 'htmlEnd', $ifExists);
    }

    /**
     * Prepends HTML to the beginning of given tag.
     *
     * @param string $tag The HTML tag that `$html` should be prepended to
     * @param string $html The HTML to prepend to `$tag`.
     * @param string|null $ifExists What to do if `$tag` already contains a child of the same type as the element
     * defined by `$html`. Set to `'keep'` if no action should be taken, or `'replace'` if it should be replaced
     * by `$tag`.
     * @return string The modified HTML
     * @since 3.3.0
     */
    public static function prependToTag(string $tag, string $html, ?string $ifExists = null): string
    {
        return self::_addToTagInternal($tag, $html, 'htmlStart', $ifExists);
    }

    /**
     * Parses an HTML tag and returns info about it and its children.
     *
     * @param string $tag The HTML tag
     * @param int $offset The offset to start looking for a tag
     * @return array An array containing `type`, `attributes`, `children`, `start`, `end`, `htmlStart`, and `htmlEnd`
     * properties. Nested text nodes will be represented as arrays within `children` with `type` set to `'text'`, and a
     * `value` key containing the text value.
     * @throws InvalidHtmlTagException if `$tag` doesn't contain a valid HTML tag
     * @since 3.3.0
     */
    public static function parseTag(string $tag, int $offset = 0): array
    {
        [$type, $start] = self::_findTag($tag, $offset);
        $attributes = static::parseTagAttributes($tag, $start, $attrStart, $attrEnd);
        $end = strpos($tag, '>', $attrEnd) + 1;
        $isVoid = $tag[$end - 2] === '/' || isset(static::$voidElements[$type]);
        $children = [];

        // If this is a void element, we're done here
        if ($isVoid) {
            $htmlStart = $htmlEnd = null;
        } else {
            // Otherwise look for nested tags
            $htmlStart = $cursor = $end;

            if (!in_array($type, ['script', 'style'])) {
                do {
                    try {
                        $subtag = static::parseTag($tag, $cursor);
                        // Did we skip some text to get there?
                        if ($subtag['start'] > $cursor) {
                            $children[] = [
                                'type' => 'text',
                                'value' => substr($tag, $cursor, $subtag['start'] - $cursor),
                            ];
                        }
                        $children[] = $subtag;
                        $cursor = $subtag['end'];
                    } catch (InvalidHtmlTagException) {
                        // We must have just reached the end
                        break;
                    }
                } while (true);
            }

            // Find the closing tag
            if (($htmlEnd = stripos($tag, "</$type>", $cursor)) === false) {
                throw new InvalidHtmlTagException("Could not find a </$type> tag in string: $tag", $type, $attributes, $start, $htmlStart);
            }

            $end = $htmlEnd + strlen($type) + 3;

            if ($htmlEnd > $cursor) {
                $children[] = [
                    'type' => 'text',
                    'value' => substr($tag, $cursor, $htmlEnd - $cursor),
                ];
            }
        }

        return compact('type', 'attributes', 'children', 'start', 'htmlStart', 'htmlEnd', 'end');
    }

    /**
     * Modifies a HTML tag’s attributes, supporting the same attribute definitions as [[renderTagAttributes()]].
     *
     * @param string $tag The HTML tag whose attributes should be modified.
     * @param array $attributes The attributes to be added to the tag.
     * @return string The modified HTML tag.
     * @throws InvalidArgumentException if `$tag` doesn't contain a valid HTML tag
     * @since 3.3.0
     */
    public static function modifyTagAttributes(string $tag, array $attributes): string
    {
        // Normalize the attributes & merge with the old attributes
        $attributes = static::normalizeTagAttributes($attributes);
        $oldAttributes = static::parseTagAttributes($tag, 0, $start, $end, true);
        $attributes = ArrayHelper::merge($oldAttributes, $attributes);

        // Ensure we don't have any duplicate classes
        if (isset($attributes['class']) && is_array($attributes['class'])) {
            $attributes['class'] = array_unique($attributes['class']);
        }

        return substr($tag, 0, $start) .
            static::renderTagAttributes($attributes) .
            substr($tag, $end);
    }

    /**
     * Parses an HTML tag to find its attributes.
     *
     * @param string $tag The HTML tag to parse
     * @param int $offset The offset to start looking for a tag
     * @param int|null $start The start position of the first attribute in the given tag
     * @param-out int $start
     * @param int|null $end The end position of the last attribute in the given tag
     * @param bool $decode Whether the attributes should be HTML decoded in the process
     * @return array The parsed HTML tag attributes
     * @throws InvalidHtmlTagException if `$tag` doesn't contain a valid HTML tag
     * @since 3.3.0
     */
    public static function parseTagAttributes(string $tag, int $offset = 0, ?int &$start = null, ?int &$end = null, bool $decode = false): array
    {
        [$type, $tagStart] = self::_findTag($tag, $offset);
        $start = $tagStart + strlen($type) + 1;
        $anchor = $start;
        $attributes = [];

        do {
            try {
                $attribute = static::parseTagAttribute($tag, $anchor, $attrStart, $attrEnd);
            } catch (InvalidArgumentException $e) {
                throw new InvalidHtmlTagException($e->getMessage(), $type, null, $tagStart);
            }

            // Did we just reach the end of the tag?
            if ($attribute === null) {
                $end = $anchor;
                break;
            }

            [$name, $value] = $attribute;
            $attributes[$name] = $value;
            $anchor = $attrEnd;
        } while (true);

        $attributes = static::normalizeTagAttributes($attributes);

        if ($decode) {
            foreach ($attributes as &$value) {
                if (is_string($value)) {
                    $value = static::decode($value);
                }
            }
        }

        return $attributes;
    }

    /**
     * Parses the next HTML tag attribute in a given string.
     *
     * @param string $html The HTML to parse
     * @param int $offset The offset to start looking for an attribute
     * @param int|null $start The start position of the attribute in the given HTML
     * @param int|null $end The end position of the attribute in the given HTML
     * @return array|null The name and value of the attribute, or `false` if no complete attribute was found
     * @throws InvalidArgumentException if `$html` doesn't begin with a valid HTML attribute
     * @since 3.7.0
     */
    public static function parseTagAttribute(string $html, int $offset = 0, ?int &$start = null, ?int &$end = null): ?array
    {
        if (!preg_match('/\s*([^=\/>\s]+)/A', $html, $match, PREG_OFFSET_CAPTURE, $offset)) {
            if (!preg_match('/(\s*)\/?>/A', $html, $m, 0, $offset)) {
                // No `>`
                throw new InvalidArgumentException("Malformed HTML tag attribute in string: $html");
            }

            // No more attributes here
            return null;
        }

        $value = true;

        // Does the tag have an explicit value?
        $offset += strlen($match[0][0]);

        if (preg_match('/\s*=\s*/A', $html, $m, 0, $offset)) {
            $offset += strlen($m[0]);

            // Wrapped in quotes?
            if (isset($html[$offset]) && in_array($html[$offset], ['\'', '"'])) {
                $q = preg_quote($html[$offset], '/');
                if (!preg_match("/$q(.*?)$q/sA", $html, $m, 0, $offset)) {
                    // No matching end quote
                    throw new InvalidArgumentException("Malformed HTML tag attribute in string: $html");
                }

                $offset += strlen($m[0]);
                if (isset($m[1]) && $m[1] !== '') {
                    $value = static::decode($m[1]);
                }
            } elseif (preg_match('/[^\s>]+/A', $html, $m, 0, $offset)) {
                $offset += strlen($m[0]);
                $value = static::decode($m[0]);
            }
        }

        $start = (int) $match[1][1];
        $end = $offset;

        return [$match[1][0], $value];
    }

    /**
     * Normalizes attributes.
     *
     * @param array $attributes
     * @return array
     * @since 3.3.0
     */
    public static function normalizeTagAttributes(array $attributes): array
    {
        $normalized = [];

        foreach ($attributes as $name => $value) {
            if ($value === false || $value === null) {
                $normalized[$name] = false;
                continue;
            }

            switch ($name) {
                case 'class':
                case 'removeClass':
                    $normalized[$name] = static::explodeClass($value);
                    break;
                case 'style':
                    $normalized[$name] = static::explodeStyle($value);
                    break;
                default:
                    // See if it's a data attribute
                    foreach (self::_sortedDataAttributes() as $dataAttribute) {
                        if (str_starts_with($name, $dataAttribute . '-')) {
                            $n = substr($name, strlen($dataAttribute) + 1);
                            $normalized[$dataAttribute][$n] = $value;
                            break 2;
                        }
                    }
                    $normalized[$name] = $value;
            }
        }

        if (isset($normalized['removeClass'])) {
            $removeClasses = ArrayHelper::remove($normalized, 'removeClass');
            $normalized['class'] = array_diff($normalized['class'] ?? [], $removeClasses);
        }

        return $normalized;
    }

    /**
     * Explodes a `class` attribute into an array.
     *
     * @param mixed $value
     * @return string[]
     * @since 3.5.0
     */
    public static function explodeClass(mixed $value): array
    {
        if ($value === null || is_bool($value)) {
            return [];
        }
        if (is_array($value)) {
            return $value;
        }
        if (is_string($value)) {
            return ArrayHelper::filterEmptyStringsFromArray(explode(' ', $value));
        }
        throw new InvalidArgumentException('Invalid class value');
    }

    /**
     * Explodes a `style` attribute into an array of property/value pairs.
     *
     * @param mixed $value
     * @return string[]
     * @since 3.5.0
     */
    public static function explodeStyle(mixed $value): array
    {
        if ($value === null || is_bool($value)) {
            return [];
        }
        if (is_array($value)) {
            return $value;
        }
        if (is_string($value)) {
            // first match any css properties that contain 'url()'
            $markers = [];
            $value = preg_replace_callback('/\burl\(.*\)/i', function($match) use (&$markers) {
                $marker = sprintf('{marker:%s}', mt_rand());
                $markers[$marker] = $match[0];
                return $marker;
            }, $value);

            // now split the styles string on semicolons
            $styles = ArrayHelper::filterEmptyStringsFromArray(preg_split('/\s*;\s*/', $value));

            // and proceed with the array of styles
            $normalized = [];
            foreach ($styles as $style) {
                [$n, $v] = array_pad(preg_split('/\s*:\s*/', $style, 2), 2, '');
                $normalized[$n] = strtr($v, $markers);
            }
            return $normalized;
        }
        throw new InvalidArgumentException('Invalid style value');
    }

    /**
     * Finds the first tag defined in some HTML that isn't a comment or DTD.
     *
     * @param string $html
     * @param int $offset
     * @return array{non-empty-string, int} The tag type and starting position
     * @throws InvalidHtmlTagException
     */
    private static function _findTag(string $html, int $offset = 0): array
    {
        // Find the first HTML tag that isn't a DTD or a comment
        if (!preg_match('/<(\/?[\w\-]+)/', $html, $match, PREG_OFFSET_CAPTURE, $offset) || $match[1][0][0] === '/') {
            throw new InvalidHtmlTagException(
                "Could not find an HTML tag in string: $html",
                isset($match[1][0]) ? strtolower($match[1][0]) : null,
                null,
                $match[0][1] ?? null
            );
        }

        return [strtolower($match[1][0]), $match[0][1]];
    }

    /**
     * Appends or prepends HTML to the beginning of a string.
     *
     * @param string $tag
     * @param string $html
     * @param string $position
     * @param string|null $ifExists
     * @return string
     */
    private static function _addToTagInternal(string $tag, string $html, string $position, ?string $ifExists = null): string
    {
        $info = static::parseTag($tag);

        // Make sure it’s not a void tag
        if (!isset($info['htmlStart'])) {
            throw new InvalidArgumentException("<{$info['type']}> can't have children.");
        }

        if ($ifExists) {
            // See if we have a child of the same type
            [$type] = self::_findTag($html);
            $child = ArrayHelper::firstWhere($info['children'], 'type', $type, true);

            if ($child) {
                return match ($ifExists) {
                    'keep' => $tag,
                    'replace' => substr($tag, 0, $child['start']) .
                        $html .
                        substr($tag, $child['end']),
                    default => throw new InvalidArgumentException('Invalid $ifExists value: ' . $ifExists),
                };
            }
        }

        return substr($tag, 0, $info[$position]) .
            $html .
            substr($tag, $info[$position]);
    }

    private static function _sortedDataAttributes(): array
    {
        if (!isset(self::$_sortedDataAttributes)) {
            self::$_sortedDataAttributes = array_merge(static::$dataAttributes);
            usort(self::$_sortedDataAttributes, fn(string $a, string $b): int => strlen($b) - strlen($a));
        }
        return self::$_sortedDataAttributes;
    }

    /**
     * Unwraps an IE conditional comment from the given HTML.
     *
     * @param string $content
     * @return array[] An array containing the HTML content, and the condition (if there is one).
     * @phpstan-return array{string,string|null}
     * @see wrapIntoCondition()
     * @since 4.0.0
     */
    public static function unwrapCondition(string $content): array
    {
        if (preg_match('/^<!--\[if (.*?)]>(?:<!-->)?\\n(.*)\\n<!(?:--<!)?\[endif]-->$/s', $content, $match)) {
            $condition = $match[1];
            $content = $match[2];
        } else {
            $condition = null;
        }

        return [$content, $condition];
    }

    /**
     * Unwraps a `<noscript>` tag from the given HTML.
     *
     * @param string $content
     * @return array[] An array containing the HTML content, and whether a `<noscript>` tag was found.
     * @phpstan-return array{string,bool}
     * @since 4.0.0
     */
    public static function unwrapNoscript(string $content): array
    {
        if (preg_match('/^<noscript>(.*)<\/noscript>$/s', $content, $match)) {
            $noscript = true;
            $content = $match[1];
        } else {
            $noscript = false;
        }

        return [$content, $noscript];
    }

    /**
     * Normalizes an element ID into only alphanumeric characters, underscores, and dashes, or generates one at random.
     *
     * @param string $id
     * @return string
     * @since 3.5.0
     */
    public static function id(string $id = ''): string
    {
        // Ignore if it looks like a placeholder
        // or starts with a placeholder (e.g. widgets > __NAMESPACE__-fieldId)
        if (preg_match('/^__[A-Z_]+__/', $id)) {
            return $id;
        }

        $id = trim(preg_replace('/[^A-Za-z0-9_.]+/', '-', $id), '-');
        return $id ?: StringHelper::randomString(10);
    }

    /**
     * Namespaces an input name.
     *
     * @param string $inputName The input name
     * @param string|null $namespace The namespace
     * @return string The namespaced input name
     * @since 3.5.0
     */
    public static function namespaceInputName(string $inputName, ?string $namespace): string
    {
        if ($namespace === null) {
            return $inputName;
        }

        return preg_replace('/([^\'"\[\]]+)([^\'"]*)/', $namespace . '[$1]$2', $inputName);
    }

    /**
     * Namespaces an ID.
     *
     * @param string $id The ID
     * @param string|null $namespace The namespace
     * @return string The namespaced ID
     * @since 3.5.0
     */
    public static function namespaceId(string $id, ?string $namespace): string
    {
        if ($namespace === null) {
            return static::id($id);
        }

        return static::id("$namespace-$id");
    }

    /**
     * Namespaces input names and other HTML attributes, as well as CSS selectors.
     *
     * This is a shortcut for calling [[namespaceInputs()]] and [[namespaceAttributes()]].
     *
     * @param string $html The HTML code
     * @param string $namespace The namespace
     * @param bool $withClasses Whether class names should be namespaced as well (affects both `class` attributes and class name CSS selectors)
     * @return string The HTML with namespaced attributes
     * @since 3.5.0
     */
    public static function namespaceHtml(string $html, string $namespace, bool $withClasses = false): string
    {
        $markers = self::_escapeTextareas($html);
        self::_namespaceInputs($html, $namespace);
        self::_namespaceAttributes($html, $namespace, $withClasses);
        return self::_restoreTextareas($html, $markers);
    }

    /**
     * Renames HTML input names so they belong to a namespace.
     *
     * This method will go through the passed-in HTML code looking for `name` attributes, and namespace their values.
     *
     * For example, this:
     *
     * ```html
     * <input type="text" name="title">
     * <textarea name="fields[body]"></textarea>
     * ```
     *
     * would become this, if it were namespaced with `foo`:
     *
     * ```html
     * <input type="text" name="foo[title]">
     * <textarea name="foo[fields][body]"></textarea>
     * ```
     *
     * @param string $html The HTML code
     * @param string $namespace The namespace
     * @return string The HTML with namespaced input names
     * @see namespaceHtml()
     * @see namespaceAttributes()
     * @since 3.5.0
     */
    public static function namespaceInputs(string $html, string $namespace): string
    {
        $markers = self::_escapeTextareas($html);
        self::_namespaceInputs($html, $namespace);
        return self::_restoreTextareas($html, $markers);
    }

    /**
     * @param string $html
     * @param string $namespace
     */
    private static function _namespaceInputs(string &$html, string $namespace): void
    {
        $html = preg_replace('/(?<![\w\-])(name=(\'|"))([^\'"\[\]]+)([^\'"]*)\2/i', '${1}' . $namespace . '[$3]$4$2', $html) ?? '';
    }

    /**
     * Prepends a namespace to `id` attributes, and any of the following things that reference those IDs:
     *
     * - `for`, `list`, `href`, `aria-labelledby`, `aria-describedby`, `aria-controls`, `data-target`, `data-reverse-target`, and `data-target-prefix` attributes
     * - ID selectors within `<style>` tags
     *
     * For example, this:
     *
     * ```html
     * <style>#summary { font-size: larger }</style>
     * <p id="summary">...</p>
     * ```
     *
     * would become this, if it were namespaced with `foo`:
     *
     * ```html
     * <style>#foo-summary { font-size: larger }</style>
     * <p id="foo-summary">...</p>
     * ```
     *
     * @param string $html The HTML code
     * @param string $namespace The namespace
     * @param bool $withClasses Whether class names should be namespaced as well (affects both `class` attributes and class name CSS selectors)
     * @return string The HTML with namespaced attributes
     * @see namespaceHtml()
     * @see namespaceInputs()
     * @since 3.5.0
     */
    public static function namespaceAttributes(string $html, string $namespace, bool $withClasses = false): string
    {
        $markers = self::_escapeTextareas($html);
        self::_namespaceAttributes($html, $namespace, $withClasses);
        return self::_restoreTextareas($html, $markers);
    }

    /**
     * @param string $html
     * @param string $namespace
     * @param bool $withClasses
     */
    private static function _namespaceAttributes(string &$html, string $namespace, bool $withClasses): void
    {
        // normalize the namespace
        $namespace = static::id($namespace);

        // Namespace & capture the ID attributes
        $ids = [];
        $html = preg_replace_callback('/(?<=\sid=)(\'|")([^\'"\s]*)\1/i', function($match) use ($namespace, &$ids): string {
            $ids[] = $match[2];
            return $match[1] . $namespace . '-' . $match[2] . $match[1];
        }, $html) ?? '';
        $ids = array_flip($ids);

        // normal HTML attributes
        $html = preg_replace_callback(
            "/(?<=\\s)((for|list|xlink:href|href|aria\\-labelledby|aria\\-describedby|aria\\-controls|data\\-target|data\\-reverse\\-target|data\\-target\\-prefix)=('|\"))([^'\"]+)\\3/i",
            function(array $match) use ($namespace, $ids): string {
                $matchIds = preg_split('/([,\s+]+)/', $match[4], flags: PREG_SPLIT_DELIM_CAPTURE);
                $namespacedIds = '';
                foreach ($matchIds as $i => $id) {
                    if (
                        $i % 2 === 0 && // not a delimiter
                        $id[0] !== '.' // not a class name
                    ) {
                        $isHash = $id[0] === '#';
                        if ($isHash) {
                            $id = substr($id, 1);
                        }
                        if (
                            isset($ids[$id]) ||
                            $match[2] === 'data-target-prefix' ||
                            ($isHash && $match[2] === 'href')
                        ) {
                            $id = sprintf('%s-%s', $namespace, $id);
                        }
                        if ($isHash) {
                            $id = "#$id";
                        }
                    }

                    $namespacedIds .= $id;
                }
                return sprintf('%s%s%s', $match[1], $namespacedIds, $match[3]);
            }, $html) ?? '';

        // ID references in url() calls
        $html = preg_replace_callback(
            "/(?<=url\\(#)[^'\"\s\)]*(?=\\))/i",
            function(array $match) use ($namespace, $ids): string {
                if (isset($ids[$match[0]])) {
                    return $namespace . '-' . $match[0];
                }
                return $match[0];
            }, $html) ?? '';

        // class attributes
        if ($withClasses) {
            $html = preg_replace_callback('/(?<![\w\-])\bclass=(\'|")([^\'"]+)\\1/i', function($match) use ($namespace) {
                $newClasses = [];
                foreach (preg_split('/\s+/', $match[2]) as $class) {
                    $newClasses[] = "$namespace-$class";
                }
                return 'class=' . $match[1] . implode(' ', $newClasses) . $match[1];
            }, $html) ?? '';
        }

        // CSS selectors
        $html = preg_replace_callback(
            '/(<style\b[^>]*>)(.*?)(<\/style>)/is',
            function(array $match) use ($namespace, $withClasses, $ids) {
                $html = preg_replace_callback(
                    "/(?<![\w'\"])#([^'\"\s]*)(?=[,\\s\\{])/",
                    function(array $match) use ($namespace, $ids): string {
                        if (isset($ids[$match[1]])) {
                            return '#' . $namespace . '-' . $match[1];
                        }
                        return $match[0];
                    }, $match[2]);
                if ($withClasses) {
                    $html = preg_replace("/(?<![\\w'\"])\\.([\\w\\-]+)(?=[,:\\s{])/", ".$namespace-$1", $match[2]);
                }
                return $match[1] . $html . $match[3];
            }, $html) ?? '';
    }

    /**
     * Replaces textareas with markers
     *
     * @param string $html
     * @return array<string, string>
     */
    private static function _escapeTextareas(string &$html): array
    {
        $markers = [];
        $offset = 0;
        $r = '';

        while (($pos = stripos($html, '<textarea', $offset)) !== false) {
            $gtPos = strpos($html, '>', $pos + 9);
            if ($gtPos === false) {
                break;
            }
            $innerHtmlPos = $gtPos + 1;
            $closePos = stripos($html, '</textarea>', $innerHtmlPos);
            if ($closePos === false) {
                break;
            }
            $outerPos = $closePos + 11;
            $innerHtml = $closePos !== $innerHtmlPos ? substr($html, $innerHtmlPos, $closePos - $innerHtmlPos) : null;

            if ($innerHtml !== null && str_contains($innerHtml, '<')) {
                $marker = sprintf('{marker:%s}', mt_rand());
                $r .= substr($html, $offset, $innerHtmlPos - $offset) . $marker . substr($html, $closePos, 11);
                $markers[$marker] = $innerHtml;
            } else {
                $r .= substr($html, $offset, $outerPos - $offset);
            }

            $offset = $outerPos;
        }

        if ($offset !== 0) {
            $html = $r . substr($html, $offset);
        }

        return $markers;
    }

    /**
     * Replaces markers with textareas.
     *
     * @param string $html
     * @param array<string, string> $markers
     */
    private static function _restoreTextareas(string $html, array $markers): string
    {
        if (empty($markers)) {
            return $html;
        }

        $r = '';
        $offset = 0;

        foreach ($markers as $marker => $textarea) {
            $pos = strpos($html, $marker, $offset);
            if ($pos !== false) {
                $r .= substr($html, $offset, $pos - $offset) . $textarea;
                $offset = $pos + strlen($marker);
            }
        }

        return $r . substr($html, $offset);
    }

    /**
     * Sanitizes an SVG.
     *
     * @param string $svg
     * @return string
     * @since 3.5.0
     */
    public static function sanitizeSvg(string $svg): string
    {
        $sanitizer = new Sanitizer();
        $sanitizer->setAllowedAttrs(new SvgAllowedAttributes());
        $svg = $sanitizer->sanitize($svg);
        // Remove comments, title & desc
        $svg = preg_replace('/<!--.*?-->\s*/s', '', $svg);
        $svg = preg_replace(self::TITLE_TAG_RE, '', $svg);
        return preg_replace('/<desc>.*?<\/desc>\s*/is', '', $svg);
    }

    /**
     * Generates a base64-encoded [data URL](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs) for the given file path.
     *
     * @param string $file The file path
     * @param string|null $mimeType The file’s MIME type. If `null` then it will be determined automatically.
     * @return string The data URL
     * @throws InvalidArgumentException if `$file` is an invalid file path
     * @since 3.5.13
     */
    public static function dataUrl(string $file, ?string $mimeType = null): string
    {
        if (!is_file($file)) {
            throw new InvalidArgumentException("Invalid file path: $file");
        }

        $file = FileHelper::absolutePath(Craft::getAlias($file), '/');

        // make sure it's contained within the project rot
        $rootPath = FileHelper::absolutePath(Craft::getAlias('@root'), '/');
        if (!str_starts_with($file, "$rootPath/")) {
            throw new InvalidArgumentException(sprintf('%s cannot be passed a path outside of the project root.', __METHOD__));
        }

        if (Craft::$app->getSecurity()->isSystemDir(dirname($file))) {
            throw new InvalidArgumentException(sprintf('%s cannot be passed a path within or above system directories.', __METHOD__));
        }

        $ext = pathinfo($file, PATHINFO_EXTENSION);
        if (strtolower($ext) === 'php') {
            throw new InvalidArgumentException(sprintf('%s cannot be passed a path to a PHP file.', __METHOD__));
        }

        if ($mimeType === null) {
            try {
                $mimeType = FileHelper::getMimeType($file);
            } catch (Throwable $e) {
                Craft::warning("Unable to determine the MIME type for $file: " . $e->getMessage(), __METHOD__);
                Craft::$app->getErrorHandler()->logException($e);
            }
        }

        return static::dataUrlFromString(file_get_contents($file), $mimeType);
    }

    /**
     * Generates a base64-encoded [data URL](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs) based on the given file contents and MIME type.
     *
     * @param string $contents The file path
     * @param string|null $mimeType The file’s MIME type. If `null` then it will be determined automatically.
     * @return string The data URL
     * @throws InvalidArgumentException if `$file` is an invalid file path
     * @since 3.5.13
     */
    public static function dataUrlFromString(string $contents, ?string $mimeType = null): string
    {
        return 'data:' . ($mimeType ? "$mimeType;" : '') . 'base64,' . base64_encode($contents);
    }

    /**
     * Inserts a non-breaking space between the last two words of a string.
     *
     * @param string $string
     * @return string
     * @since 3.7.0
     */
    public static function widont(string $string): string
    {
        return preg_replace('/(?<=\S)\s+(\S+\s*)$/', '&nbsp;$1', $string);
    }

    /**
     * Returns a visually-hidden input label.
     *
     * @param string $content
     * @param string|null $for
     * @param array $options
     * @return string
     * @since 4.0.0
     */
    public static function hiddenLabel(string $content, ?string $for = null, array $options = []): string
    {
        return static::label($content, $for, array_merge($options, [
            'class' => array_merge(static::explodeClass($options['class'] ?? []), [
                'visually-hidden',
            ]),
        ]));
    }

    /**
     * Encodes invalid (unclosed) HTML tags so they appear as plain text.
     *
     * @param string $html
     * @return string
     * @since 3.7.27
     */
    public static function encodeInvalidTags(string $html): string
    {
        $offset = 0;
        $return = '';

        while (true) {
            try {
                $tag = static::parseTag($html, $offset);
            } catch (InvalidHtmlTagException $e) {
                if ($e->type === null) {
                    // No more HTML tags in the string
                    return $return . substr($html, $offset);
                }

                if ($e->htmlStart) {
                    $preTagLength = $e->start - $offset;
                    $innerTagOffset = $e->start + 1;
                    $innerTagLength = $e->htmlStart - $innerTagOffset - 1;
                    $return .= sprintf('%s&lt;%s&gt;', substr($html, $offset, $preTagLength), substr($html, $innerTagOffset, $innerTagLength));
                    $offset = $e->htmlStart;
                } else {
                    // Found a tag, but it wasn't closed (e.g. `<input`)
                    $newOffset = $e->start + strlen($e->type) + 1;
                    $return .= substr($html, $offset, $newOffset - $offset);
                    $offset = $newOffset;
                }

                continue;
            }

            $return .= substr($html, $offset, $tag['end'] - $offset);
            $offset = $tag['end'];
        }
    }

    /**
     * Decodes any double-encoded entities.
     *
     * @param string $html
     * @return string
     * @since 5.8.3
     */
    public static function decodeDoubles(string $html): string
    {
        return preg_replace('/&amp;(\w+);/', '&$1;', $html);
    }

    /**
     * Returns the contents of a given SVG file.
     *
     * @param string|Asset $svg An SVG asset, a file path, or raw SVG markup
     * @param bool|null $sanitize Whether the SVG should be sanitized of potentially
     * malicious scripts. By default, the SVG will only be sanitized if an asset
     * or markup is passed in. (File paths are assumed to be safe.)
     * @param bool|null $namespace Whether class names and IDs within the SVG
     * should be namespaced to avoid conflicts with other elements in the DOM.
     * By default, the SVG will only be namespaced if an asset or markup is passed in.
     * @param bool $throwException Whether to throw an exception on error
     * @return string
     * @since 4.3.0
     */
    public static function svg(
        Asset|string $svg,
        ?bool $sanitize = null,
        ?bool $namespace = null,
        bool $throwException = false,
    ): string {
        if ($svg instanceof Asset) {
            try {
                $svg = $svg->getContents();
            } catch (Throwable $e) {
                if ($throwException) {
                    throw $e;
                }
                Craft::error("Could not get the contents of {$svg->getPath()}: {$e->getMessage()}", __METHOD__);
                Craft::$app->getErrorHandler()->logException($e);
                return '';
            }
        } elseif (stripos($svg, '<svg') === false) {
            // No <svg> tag, so it's probably a file path
            try {
                $svg = Craft::getAlias($svg);
            } catch (InvalidArgumentException $e) {
                if ($throwException) {
                    throw $e;
                }
                Craft::error("Could not get the contents of $svg: {$e->getMessage()}", __METHOD__);
                Craft::$app->getErrorHandler()->logException($e);
                return '';
            }
            if (!is_file($svg) || !FileHelper::isSvg($svg)) {
                if ($throwException) {
                    throw new InvalidArgumentException("Invalid SVG path: $svg");
                }
                Craft::warning("Could not get the contents of $svg: The file doesn't exist", __METHOD__);
                return '';
            }
            $svg = file_get_contents($svg);

            // This came from a file path, so pretty good chance that the SVG can be trusted.
            $sanitize ??= false;
            $namespace ??= false;
        }

        // Sanitize and namespace the SVG by default
        $sanitize ??= true;
        $namespace ??= true;

        // Sanitize?
        if ($sanitize) {
            $svg = Html::sanitizeSvg($svg);
        }

        // Remove the XML declaration
        $svg = preg_replace('/<\?xml.*?\?>\s*/', '', $svg);

        // Namespace class names and IDs
        if ($namespace) {
            $ns = StringHelper::randomString(10);
            $svg = Html::namespaceAttributes($svg, $ns, true);
        }

        return $svg;
    }
}
